The collection comprises primarily letters and copies of letters by members of the Monsell family or individuals associated with them. Of particular note is a letter book kept by the shipping merchant William Monsell (P2/1/1), which contains copies of some 1,200 items of mainly business correspondence, giving a unique insight into Limerick as a maritime mercantile city in the early eighteenth century. Of equal interest is the fragment of a diary (P2/1/12) kept by his grandson, the Reverend Samuel Monsell (1743-1818), Precentor of Ardfert from 1791 to 1811, which provides an extraordinary account of the private life and innermost thoughts of a Church of Ireland clergyman struggling to stay on the path of virtue.